Include const generic arguments in metadata.

src/librustc_metadata/encoder.rs

@@ -5,7 +5,7 @@ use rustc::middle::cstore::{LinkagePreference, NativeLibrary,
                             EncodedMetadata, ForeignModule};
 use rustc::hir::def::CtorKind;
 use rustc::hir::def_id::{CrateNum, CRATE_DEF_INDEX, DefIndex, DefId, LocalDefId, LOCAL_CRATE};
-use rustc::hir::GenericParamKind;
+use rustc::hir::{GenericParamKind, AnonConst};
 use rustc::hir::map::definitions::DefPathTable;
 use rustc_data_structures::fingerprint::Fingerprint;
 use rustc_index::vec::IndexVec;
@@ -1711,6 +1711,11 @@ impl Visitor<'tcx> for EncodeContext<'tcx> {
         intravisit::walk_expr(self, ex);
         self.encode_info_for_expr(ex);
     }
+    fn visit_anon_const(&mut self, c: &'tcx AnonConst) {
+        intravisit::walk_anon_const(self, c);
+        let def_id = self.tcx.hir().local_def_id(c.hir_id);
+        self.record(def_id, EncodeContext::encode_info_for_anon_const, def_id);
+    }
     fn visit_item(&mut self, item: &'tcx hir::Item) {
         intravisit::walk_item(self, item);
         let def_id = self.tcx.hir().local_def_id(item.hir_id);
@@ -1728,25 +1733,10 @@ impl Visitor<'tcx> for EncodeContext<'tcx> {
                           EncodeContext::encode_info_for_foreign_item,
                           (def_id, ni));
     }
-    fn visit_variant(&mut self,
-                     v: &'tcx hir::Variant,
-                     g: &'tcx hir::Generics,
-                     id: hir::HirId) {
-        intravisit::walk_variant(self, v, g, id);
-
-        if let Some(ref discr) = v.disr_expr {
-            let def_id = self.tcx.hir().local_def_id(discr.hir_id);
-            self.record(def_id, EncodeContext::encode_info_for_anon_const, def_id);
-        }
-    }
     fn visit_generics(&mut self, generics: &'tcx hir::Generics) {
         intravisit::walk_generics(self, generics);
         self.encode_info_for_generics(generics);
     }
-    fn visit_ty(&mut self, ty: &'tcx hir::Ty) {
-        intravisit::walk_ty(self, ty);
-        self.encode_info_for_ty(ty);
-    }
     fn visit_macro_def(&mut self, macro_def: &'tcx hir::MacroDef) {
         let def_id = self.tcx.hir().local_def_id(macro_def.hir_id);
         self.record(def_id, EncodeContext::encode_info_for_macro_def, macro_def);
@@ -1784,16 +1774,6 @@ impl EncodeContext<'tcx> {
         }
     }
 
-    fn encode_info_for_ty(&mut self, ty: &hir::Ty) {
-        match ty.kind {
-            hir::TyKind::Array(_, ref length) => {
-                let def_id = self.tcx.hir().local_def_id(length.hir_id);
-                self.record(def_id, EncodeContext::encode_info_for_anon_const, def_id);
-            }
-            _ => {}
-        }
-    }
-
     fn encode_info_for_expr(&mut self, expr: &hir::Expr) {
         match expr.kind {
             hir::ExprKind::Closure(..) => {

src/test/ui/const-generics/auxiliary/const_generic_lib.rs

@@ -0,0 +1,9 @@
+#![feature(const_generics)]
+
+pub struct Struct<const N: usize>(pub [u8; N]);
+
+pub type Alias = Struct<2>;
+
+pub fn function(value: Struct<3>) -> u8 {
+    value.0[0]
+}

src/test/ui/const-generics/const-argument-cross-crate-mismatch.rs

@@ -0,0 +1,10 @@
+// aux-build:const_generic_lib.rs
+
+extern crate const_generic_lib;
+
+fn main() {
+    let _ = const_generic_lib::function(const_generic_lib::Struct([0u8, 1u8]));
+    //~^ ERROR mismatched types
+    let _: const_generic_lib::Alias = const_generic_lib::Struct([0u8, 1u8, 2u8]);
+    //~^ ERROR mismatched types
+}

src/test/ui/const-generics/const-argument-cross-crate-mismatch.stderr

@@ -0,0 +1,21 @@
+error[E0308]: mismatched types
+  --> $DIR/const-argument-cross-crate-mismatch.rs:6:41
+   |
+LL |     let _ = const_generic_lib::function(const_generic_lib::Struct([0u8, 1u8]));
+   |                                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `3usize`, found `2usize`
+   |
+   = note: expected type `const_generic_lib::Struct<3usize>`
+              found type `const_generic_lib::Struct<_: usize>`
+
+error[E0308]: mismatched types
+  --> $DIR/const-argument-cross-crate-mismatch.rs:8:39
+   |
+LL |     let _: const_generic_lib::Alias = const_generic_lib::Struct([0u8, 1u8, 2u8]);
+   |                                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ expected `2usize`, found `3usize`
+   |
+   = note: expected type `const_generic_lib::Struct<2usize>`
+              found type `const_generic_lib::Struct<_: usize>`
+
+error: aborting due to 2 previous errors
+
+For more information about this error, try `rustc --explain E0308`.

src/test/ui/const-generics/const-argument-cross-crate.rs

@@ -0,0 +1,12 @@
+// run-pass
+// aux-build:const_generic_lib.rs
+
+extern crate const_generic_lib;
+
+struct Container(const_generic_lib::Alias);
+
+fn main() {
+    let res = const_generic_lib::function(const_generic_lib::Struct([14u8, 1u8, 2u8]));
+    assert_eq!(res, 14u8);
+    let _ = Container(const_generic_lib::Struct([0u8, 1u8]));
+}